Predators like it hot: Thermal mismatch in a predator–prey system across an elevational tropical gradient

Abstract

Climate change may have dramatic consequences for communities through both direct effects of peak temperatures upon individual species and through interspecific mismatches in thermal sensitivities of interacting organisms which mediate changes in interspecific interactions (i.e. predation). Despite this, there is a paucity of information on the patterns of spatial physiological sensitivity of interacting species (at both landscape and local scales) which could ultimately influence geographical variation in the effects of climate change on community processes. In order to assess where these impacts may occur, we first need to evaluate the spatial heterogeneity in the degree of mismatch in thermal tolerances between interacting organisms. We quantify the magnitude of interspecific mismatch in maximum (CTmax) and minimum (CTmin) thermal tolerances among a predator–prey system of dragonfly and anuran larvae in tropical montane (242–3,631 m) and habitat (ponds and streams) gradients. To compare thermal mismatches between predator and prey, we coined the parameters maximum and minimum predatory tolerance margins (PTMmax and PTMmin), or difference in CTmax and CTmin of interacting organisms sampled across elevational and habitat gradients. Our analyses revealed that: (a) predators exhibit higher heat tolerances than prey (~4°C), a trend which remained stable across habitats and elevations. In contrast, we found no differences in minimum thermal tolerances between these groups. (b) Maximum and minimum thermal tolerances of both predators and prey decreased with elevation, but only maximum thermal tolerance varied across habitats, with pond species exhibiting higher heat tolerance than stream species. (c) Pond‐dwelling organisms from low elevations (0–1,500 m a.s.l.) may be more susceptible to direct effects of warming than their highland counterparts because their maximum thermal tolerances are only slightly higher than their exposed maximum environmental temperatures. The greater relative thermal tolerance of dragonfly naiad predators may further increase the vulnerability of lowland tadpoles to warming due to potentially enhanced indirect effects of higher predation rates by more heat‐tolerant dragonfly predators. However, further experimental work is required to establish the individual and population‐level consequences of this thermal tolerance mismatch upon biotic interactions such as predator–prey. ​

Elevational and local climate variability predicts thermal breadth of mountain tropical tadpoles

“…Our results indicate that highland and pond-dwelling tadpole species have broader thermal breadths than lowland and stream-restricted species, supporting the climate variability hypothesis at both large spatial scales (Stevens 1989, Sheldon and Tewksbury 2014, Shah et al 2017, Pintanel et al 2019) and local microenvironmental scales (Kaspari et al 2015, Baudier et al 2018, Pintanel et al 2019, 2021. At a large spatial scale (i.e.…”

“…Centrolenidae family, Atelopus and Hyloscirtus genus; Fig. 1 and 3) show lower CT max than species that can exploit temporal ponds (Duarte et al 2012, Gutiérrez-Pesquera et al 2016, Pintanel et al 2021. Species might select suitable habitats within an elevational band instead of being exposed to maximum extreme temperatures and, thus, habitat selection might have buffered CT max evolution (Muñoz et al 2014, Muñoz andBodensteiner 2019).…”

“…Although none of the upland species seem to be exposed to maximum temperatures closer to their heat tolerance, the rise of temperatures may increase nonlethal chronic stress (Sinclair et al 2016). In addition, the increase of temperatures can also alter the intensity of biotic interactions (Pintanel et al 2021), with the eventual upward migration of lowland species, threatening their survival in the long/medium term. Effects of global warming may manifest more strongly than expected in stream‐ and forest‐restricted species.…”

“…We estimated thermal limits for 1890 specimens from 75 species (Supporting information) using the same methodology as Pintanel et al (2021). Before the experiments, larvae were acclimated at 20°C using a portable thermal bath (patent license ES1135983U; Madrid, Spain) with a photoperiod of 12L:12D for at least three days to stabilize thermal tolerance estimates of field sampled individuals living at diverse environmental temperatures (Hutchison 1961, Brattstrom 1968).…”

Warming and predation risk only weakly shape size-mediated priority effects in a cannibalistic damselfly

“…(1) I. elegans shows SMPE in life history and physiological traits. We expected early hatchlings to have advantage over late hatchlings in terms of food acquisition, including cannibalism, leading early hatchlings to show higher values for life history traits (survival, development rate and mass at emergence) and physiological traits (increased energy storage in fat and proteins, and an increased investment in immune function measured as phenoloxidase activity) 4,9,47−50 . (2) SMPE is more pronounced or more likely at the higher temperature as this leads to increased food acquisition through increased activity [51][52][53][54] , and more/earlier cannibalism, 22 but see 55 . (3) SMPE in life history and physiological traits is less pronounced when larvae experience additional stress imposed by top predator cues.…”